Thylakoid and Photosystem Biogenesis
Where does life on Earth get its energy? It can all be traced back to one enzyme: photosystem II (PSII). Plants, algae and cyanobacteria convert light energy into chemical energy in a process called photosynthesis. These organisms transform the greenhouse gas carbon dioxide (CO2) into biomass in gigaton scale per year and release oxygen as a byproduct. Heterotrophic organisms, including humans, convert plant biomass back to CO2 and use the oxygen to supply their own metabolism with energy to complete this bioenergetic circle of life. PSII plays a unique role in this process, as it is the only enzyme that can split water into protons, oxygen and electrons, provided the energy needed to fix CO2.
This unique molecular machine is composed of more than 100 parts that all have to be placed in precise positions to construct a functional complex. Humans have developed the concept of an assembly line to coordinate the construction of a complex machine in time and space: parts are preassembled into modules at specific workstations, and the modules are then moved to the next step in the assembly line. Nature has found a similar solution. The assembly of PSII is facilitated by more than 20 protein factors that help construct a functional complex. However, the molecular mechanisms of these assembly factors remain largely unknown.
Molecular Assembly line of Photosystem II
Our Lab is interested in obtaining a comprehensive view of the entire PSII assembly line. We are analyzing the molecular details of this pathway to develop a comprehensive model for PSII assembly in time and space that illustrates the general concept of Nature’s molecular assembly lines. In this effort, we are working closely together with our close friends the Nowaczyk Lab (RUB), distinguished experts in PSII biochemistry and spectroscopy. Current work in the lab focuses on how the unique metallocluster cluster, the water oxidizing center of PSII is actually formed. One of the major questions of contemporary biology. The work on this project is generously supported by the Daimler Benz foundation.